something the white houses strongly denying. >>> all right, andrea mitchell, thank you, we want to let you know about a special broadcast in the works for monday. brian will be here to bring you a series of reports we're calling "at the brink" including ann curry, and richard engel in syria, and more. a hard look at some of the most dangerous conflicts in the world, and here at home, special coverage will start sunday on nightly news. >>> and on the presidential campaign trail today, mitt romney acknowledges he is fighting an uphill battle in the battleground state of pennsylvania, but he maintains he can win there, as attention is already turning to the debates next week, which could be a game-changer. good evening, peter. >> reporter: savannah, good evening to you, this weekend both mitt romney and the president have light schedules planned. instead, they will be hunkering down in private, focusing on trying to refine their message ahead of next week's debate, that will be watched by the largest audience that either of them has seen all campaign. rallying supporters in pennsylvania t